Process for the fabrication of metal products

ABSTRACT

IN A PROCESS FOR THE FABRICATION OF METAL PRODUCTS BY STAMPING OUT BLANKS MADE IN A STRIP OF METAL AND FINAL FORMING, THERE ARE PROVIDED THE STEPS OF STAMPING OUT A ROUGH-SHAPING IN THE FORM OF A CUP, SEPARATING THE ROUGHSHAPING FROM THE STRIP, RE-INTRODUCING SAID ROUGH-SHAPING   INTO ITS FORMER PLACE IN THE STRIP WHERE IT IS MAINTAINED AND EXECUTING ON SAID MAINTAINED ROUGH-SHAPING THE FINAL FORMING OPERATIONS AND EXPELLING THE FINISHED PRODUCT.

Oct. 5, 1971 LACHAUSSEE EIAL 3,609,852

PROCESS FOR THE FABRICATION OF METAL PRODUCTS Filed 001;. 24, 1969 I Ilam United States Patent Gee 3,609,852 PROCESS FOR THE FABRICATION OFMETAL PRODUCTS Maurice Lachaussee, 360 Rue de lYser, Ans-lez-Liege,

Belgium, and Andre Maigret, 4 Avenue de la Grange, Val de Mare, France 7Filed Oct. 24, 1969, Ser. No. 869,262

Claims priority, application lsielginm, Dec. 20, 1968,

Int. Cl. nzs 17/00 U.S. Cl. 29-412 5 Claims ABSTRACT OF THE DISCLOSUREThe invention relates to a process for the fabrication of metal productsfrom blanks made in a strip of metal.

The fabrication of certain hollow metal products such as, for example,hollow bodies provided with an expanded portion are at present made ontwo separate machines. Initially, in a first machine, there is formed,in a strip of metal, blanks which are directly submitted to stamping toconstitute cups which are detached from the rest of the strip; thesecups are then taken up again, one by one, by pliers and transferred to asecond machine which executes in a known manner a localised enlargementwith the help of a die with a widened tip constituted of several parts.

This method of fabrication has two important disadvantages which, byslowing down the production, diminish the yield and increase the costprice: this known method requires two separate machines, one for thestamping and cutting, and the other for the enlargement of the cup; onthis second machine the cups are treated one by one and are manipulatedby transfer pliers.

According to the invention, there is provided a process for thefabrication of metal products by stamping out blanks made in a strip ofmetal and final forming, the process comprising the steps of stampingout a roughshaping in the form of a cup, separating the rough-shapingfrom the strip, re-introducing the rough-shaping into the space which itoccupied in the strip so that the roughshaping is held by the strip,executing the final forming operations on the rough-shaping thus held bythe strip, and expelling the finished product.

In accordance with a preferred feature the rough-shaping formed isseparated from the strip by the action of a die which introduces it intoa cutting matrix against the action of a support submitted to thepermanent thrust of a spring which pushes the said rough-shaping backinto the strip as soon as the die is retracted; because of this the partconstituting the waste of the strip is used to hold the rough-shapingwhich is re-introduced into it after separation and can thus undergo thesubsequent operations as if it were gripped in transfer pliers.

The invention will be further described with reference to theaccompanying drawings, which illustrate applications of the invention,given only by way of example.

FIGS. 1 to 5 are schematic sectional views of the various phases offabrication of a hollow component provided with a peripheral enlargementnear the base;

FIGS. 6 and 7 are schematic sectional views of two 3,699,852 PatentedOct. 5., 1971 phases of fabrication of a hollow component provided withan elastic component; and

FIGS. 8 and 9 are similar views relating to the fabrication of a hollowrivet.

All these schematic figures show only the phases which are useful to thecomprehension of the invention, the others having been omitted.

With the help of a press of known type, not described here, there isfirst made in a strip of sheet metal 2 a series of circular blanks fromwhich, after having made the strip advance by one pass, there are thenstamped out a series of rough-shapings in the form of cups such as 1(FIG. 1) which are still attached to the rest of the strip 2. In thefollowing phase, and after having advanced the strip 2 by another pass,the cup 1 is separated by cutting according to its external diameter; inorder to do this, a die 3 pushes down the cup 1 lodged in the cuttingmatrix 4, on a sliding support 5 subjected to the permanent thrust of aspring 6 (FIG. 2). As soon as it has arrived at the bottom of the coursetowards the base against the action of the spring 6, the cup is pushedback upwards in such a manner that the cup 1 which has just beenseparated is re-introduced into the strip 2 at the same part of theblank from which it has been obtained; the strip 2 is held in positionby a blank press 13 held by springs 14, and the cup is held in place bythe rest of the strip (FIG. 3).

After this phase, in the course of which the cutting-oft of the cup andits re-introduction into the strip is effected, the strip is once moreadvanced by a pass to bring the cup, still held in the strip, under ahollow die with a widened tip, in several parts, of a known type (FIG.4); in the course of this phase the cup is deformed near its base 1awhere there is formed a peripheral swelling 1b; after this operation,the strip 2 is advanced by another pass with the cup 1, which has justbeen provided with the swelling 1b and which is still held gripped bythe strip, and a sliding finger is dropped to disengage it from thestrip in such a manner that it is freed and can be led towards its finaldestination.

It should be noted that the process described above allows for theexecution of all the various operations necessary for the fabrication ofenlarged hollow bodies on a single machine from metal strips which cancomprise, next to each other, several rows of blanks at the start, andat the end of the operations several rows of finished bodies.

The process can be applied to the fabrication of other bodies likeencased pieces or press-studs.

On a known machine and in accordance with the process which has justbeen described, there are fabricated, from a strip 9 of sheet metal,cups such as the one referenced 8 in FIG. 6, the cup 8 beingreintroduced into the strip 9. The three first fabrication phases of apressstud are identical with the phases described with reference toFIGS. 1, 2, 3; however, it should be noted that the cup 8 is not as tallas the cup 1 and its bottom has a projection 8a.

The cup 8 having been formed and having been reintroduced into theremainder of the strip 9 in the manner explained above, there is lodgedin it an elastically deformable metal ring 10 (FIG. 6) forming a spring;encasement is then proceeded with by folding down on the ring 10 (FIG.7) the edge of the cup 8, still held in the strip 9 which then advancesby another pass to allow the ejection of the finished piece by a finger(not shown). In this case, the ring forming the spring 10 is fabricatedseparately on a special machine but its assembly with the cup is made onthe machine on which this cup is fabricated.

By a similar process there can also be fabricated eyelets or tubularrivets obtained by the assembly of a ring forming the head with a pieceforming the body. On a first machine, the body 11 is fabricated and thenis placed on a cup 12. fabricated on a second machine in accordance Withthe process described above (FIG. 8); the assembly with the cup 12 iseffected on the machine for the fabrication of this cup by an operationsimilar to encasing, by bending back hi edge 12a (FIG. 9).

The invention is not limited to the cases of application which have justbeen described and Without departing from its scope it is possible tomake certain modifications With a view to its application to numerousfabrications.

Among the various advantages of the process, there can be cited theabolition of certain machines and transfer pliers as Well as theincrease in yield.

We claim:

1. A process for the fabrication of metal products by stamping outblanks made in a strip of metal and final forming, the processcomprising the steps of stamping out a rough-shaping in the form of acup, separating the rough-shaping from the strip, re-introducing theroughshaping into the space which it occupied in the strip so that therough-shaping is held by the strip, executing the final formingoperations on the rough-shaping thus held by the strip, and expellingthe finished product.

2. A process as claimed in claim 1 in which the roughshaping isseparated by the action of a die which introduces the rough-shaping intoa guide element against the action of a sliding support.

3. A process as claimed in claim 2, in Which the roughshaping separatedfrom the strip is re-introduced into the strip by the action of thesliding support, which is submitted to the permanent thrust of a spring,as soon as the separation die is retracted.

4. A process as claimed in claim 3, in Which the roughshapingre-introduced into the strip is submitted to a localised expansionoperation by the action of a die with a projection comprising severalparts.

5. A process as claimed in claim 3, in which complementary pieces arelodged in the respective rough-shapings re-introduced into the strip,and assembly is completed by an encasement step.

References Cited UNITED STATES PATENTS 1,161,191 11/1915 Cook 294182,324,205 7/1943 Gladfelter et al.

l13120 (H) UX 3,015,884 1/1962 Chamberlain 2942.3 3,094,197 6/1963Attwood 29-522 X 3,302,441 2/1967 Bozek 113120 (H) X CHARLIE T. MOON,Primary Examiner US. Cl. X.R.

